Voir la notice de l'article provenant de la source Math-Net.Ru
@article{MM_1995_7_5_a36, author = {G. A. Smolkin}, title = {On the hypoellipticity of a~special class of differential operators}, journal = {Matemati\v{c}eskoe modelirovanie}, pages = {63}, publisher = {mathdoc}, volume = {7}, number = {5}, year = {1995}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MM_1995_7_5_a36/} }
G. A. Smolkin. On the hypoellipticity of a~special class of differential operators. Matematičeskoe modelirovanie, Tome 7 (1995) no. 5. http://geodesic.mathdoc.fr/item/MM_1995_7_5_a36/